Occasionally, users have a need to send an email to a recipient whose email address users do not know. However, in many such instances, users know the recipient's mobile phone number, i.e., its International Mobile Subscriber Identity (IMSI). Traditional email systems do not allow sending of an email without it valid email address. Accordingly, there is a need in the art for a way to not only send an email to any IMSI without knowing anything else, but also to use existing entailing features to send such email to any IMSI without requiring lots of configuration and hassle.